Aligana was working at the American embassy in Nairobi, Kenya. On August 7, 1998, at the age of 21, Aliganga was killed by a car-bomb explosion, along with eleven fellow Americans, in the suicide bomb attack. Aliganga was the only U.S. Marine who was killed in the attack in Kenya. This was part of a simultaneous suicide bomb attack in which car bombs were exploded at U.S. embassies in Tanzania and Kenya, killing 257 people and wounding over 4,000. The attack was later determined to be conducted by the al-Qaeda network and Osama bin Laden.

In early January 1998, based on recommendations from his superiors, Aliganga was sent to the elite Marine Security Guard School, in MCB Quantico, Virginia. Upon completing the rigorous training, Aliganga requested the American embassy in Nairobi, Kenya. In late February 1998, his request was approved and he was assigned to one tour of special duty at the U.S. embassy in Kenya, where he worked until his death on August 7, 1998, when the embassy was attacked by terrorists.